POJO Date property set to null ends up set to 1969-12-31

rnmixon · **Joined:** Tue Sep 09, 2003 5:20 pm **Posts:** 43

What is the correct way to set a Date property to null such that both Java and SQL will treat/see it as null.

Thanks in advance - Richard

Hibernate version:
2.1.8

Mapping documents:

Code:

<hibernate-mapping>
    <class name="com.acme.persistence.PoMeasurementItem" table="PoMeasurementItem" proxy="com.acme.persistence.PoMeasurementItem" dynamic-update="false" dynamic-insert="false" select-before-update="false" optimistic-lock="version" >
        <id name="id"type="long" unsaved-value="null" >
                <column name="id"  unique-key="id" />
            <generator class="native"></generator>
        </id>
        <version name="version" type="int"
            column="version" access="property" unsaved-value="undefined" />
        <many-to-one name="measurementItemSet" class="com.acme.persistence.PoMeasurementItemSet"
            cascade="none" outer-join="true" update="true" insert="true"
            access="property" >
            <column name="measurementItemSet" unique-key="userkey" />
        </many-to-one>
        <property name="liNum" type="int" update="true" insert="true"
            access="property" column="liNum" />
        <property name="reviewDate" type="java.sql.Date"
            update="true" insert="true" access="property" >
            <column name="reviewDate"  unique-key="userkey" />
        </property>
        <set name="assessmentItems" table="PoAssessmentItem" lazy="true"
            inverse="true" cascade="all" sort="unsorted" >
              <key column="measurementItem"></key>
              <one-to-many class="com.acme.persistence.PoAssessmentItem" />
        </set>
    </class>
</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():

Code:

            ...
            java.sql.Date reviewDate = null;
            for (int i=0; i<ps.getProblemCt();i++) {
                PoMeasurementItem mi = new PoMeasurementItem();
                mi.setLiNum(i);
                mis.addMeasurementItem(mi);
                mi.setReviewDate(reviewDate);
            }
            ...
            if (cmMI != null) {
                userTx.getSession().save(cm.getMeasurementParms());
                userTx.getSession().save(cm);
                userTx.getSession().flush();
            }
            ...

Later the check below to see if the ReviewDate is null fails:

Code:

            PoMeasurementItem measurementItem = ai.getMeasurementItem();
            if (reviewItem && measurementItem.getReviewDate() == null ) {
                measurementItem.setReviewDate(assessment.getAssessmentDate());
            }

Also, the query
select * from PoMeasurementItem where reviewDate is null ;
returns no rows from the database as they are all set to '1969-12-31'.

Full stack trace of any exception that occurs:
No exception - but value of 1969-12-31 is stored in the database.

Name and version of the database you are using:
MySQL 4.1.7

The generated SQL (show_sql=true):

Code:

create table PoMeasurementItemSet (
   id BIGINT NOT NULL AUTO_INCREMENT,
   version INTEGER not null,
   classMeasurement BIGINT not null,
   problemSet BIGINT not null,
   lisNum INTEGER not null,
   primary key (id),
   unique (classMeasurement, problemSet)
) type=InnoDB ;

Debug level Hibernate log excerpt:
N/A

rnmixon · **Joined:** Tue Sep 09, 2003 5:20 pm **Posts:** 43

BTW, I have searched the forum (using "MySQL Date null 1969-1231" and googled, as well as Hibernate in Action, the reference manual. FAQ and Wiki. If I've overlooked this, apologies but I really did look.

magic · **Posted:** Thu Mar 24, 2005 4:56 am

Just a suggestion : 1969-12-31 seems to be 1970-01-01 with a negative timezone. Maybe should you search in this way...

rnmixon · **Joined:** Tue Sep 09, 2003 5:20 pm **Posts:** 43

Thanks for the suggestion - but running my searches scans using 1970-01-01 did not turn up any new relant information on how to check for a null Date property for a Hibernate persisted object.

Still looking - I really hate to thing I'm going to have to hardcode something like:

Code:

  if ( measItem.getReviewDate() == null || measItem.equals('1969-12-31') ) {
...
  }

rnmixon · **Joined:** Tue Sep 09, 2003 5:20 pm **Posts:** 43

One more example of what too little sleep can do to you.

My POJO getter was using a nullSafe method to return a default of "new Date(0)" when Date was null.

Sincere apologies for wasting anybody's time.

-Richard